Hand-held motor-driven shear



c. B. GRAY HELD MOTOR- April 27, 1954 HAND- DRIVEN SHEAR Filed Oct. 10, 1951' {23 Ill] INVENTOR cm RLEs s. GRHY ATTORNEY Patented Apr. 27,1954 r A 2,676,403 HAND-HELD MOTOR-DRIVEN SHEAR Charles B. Gray, Springfield, Pa. Rosa Gray,

executrix of said Charles B.

Gray, deceased Application October 10, 1951, Serial No. 250,730

1 Claim.

This invention relates generally to tools for cutting sheet metal and similar stock' and is more particularly concerned with an improved construction of hand-held, electrically operated shears afiording particular advantage as to the replacement of broken or damaged parts without undue restriction of the utility of the tool.

Known motor driven sheet metal cutting tools commonly are constructed with a frame mounting, a motor having a power shaft operated by the motor and imparting reciprocating motion to a member mounting a shear blade. One class of such tools is provided with an anvil having a vertically extending portion afiording guiding means for a reciprocable member carrying a cutter blade and a holding portion for the fixed blade, both of the aforementioned portions being integrally formed with, and disposed at opposite ends of, a deflector plate having an upper flat surface spiralling smoothly downward from one side of the base of the vertically extending guiding portion to the other side thereof and terminating in the holding portion for the fixed blade. In another class of such tools the means for guiding the reciprocating member i not integral with the anvil, which is a member generally arcuate in shape and comprising a horizontal attaching portion and a holding portion for the fixed blade, both of the aforementioned portions being integrally formed with, and disposed at opposite ends of, a deflector plate having an upper flat surface which is depressed relative to the upper flat surface of the attaching portion. The attaching portion is detachably secured to the underside of a complemental flange projecting from one side of a base portion of the vertically extending guiding means, and when the attaching portion is so secured in place, the depressed upper fiat surface of the deflector plate spirals smoothly downward from the attaching portion to the other side of the vertically extending guiding means and terminates in the holding portion for the fixed blade. Neither of the aforementioned constructions has proved to be entirely satisfactory. When the guiding means is made integral with the anvil, the cost of replacing the part when broken or injured in operation is unduly high, and when the guiding means is not made integral with the anvil, the upper flat surfaces of the complemental flange and the deflector plate do not merge smoothly, and, consequently, the utility of the tool is unduly limited with regard to making cuts along a line curving to the right.

Accordingly, it is an object of this invention 2 to provide a motor driven sheet metal cutting tool with suitable means for guiding the reciprocable member and with a separate anvil detachably securable thereto in working position in a manner which avoids undue restriction of the usefulness of the tool.

Other objects and advantages of the present invention will appear more fully hereinafter, it being understood that the present invention consists in the combination, construction, location and relative arrangement of parts, all as will be more fully described hereinafter, as is shown in the accompanying drawings and will be pointed out in the appended claim.

In the accompanying drawings:

Figure 1 is a side elevation of a shear constructed in accordance with and embodying the principles of the invention, part being shown in section. V

Figure 2 is an enlarged plan section on line 2-2 of Figure 1.

Figure 3 is a perspective plan section on line 2-2 of Figure 1.

Figure 4 is a section on line 4-4 of Figure 2.

Figure 5 is a perspective elevation showing the anvil separated from the rest of the operating head of the tool.

Figure 6 is a perspective elevation showing the pieces of Figure 5 assembled.

Figure 7 is an elevation on ure 2.

Referring now more particularly to the drawings, it will be observed that the tool of the present invention is or a adapted to be held conveniently in the hand of the operator, the operating head of the tool, designated generally by the reference numeral l0, being secured to the forward end of a casing H in which is housed an electric motor it for driving a main shaft it through the intervention of a gear train designated generally by the numeral M. The construction of the casing H and the design and disposition of the motor I2 and the gear train l4 therein may be varied as desired, it being merely noted in this connection that the casing H is adapted to be conveniently held in the hand of the operator and is fitted with a finger actuated electric switch It for controlling the operation of the motor.

The operating head it comprises a guide sleeve l1 and an anvil i8 depending from the casing 11, and a member 19 reciprocably mounted within the guide sleeve ll. -he latter has a tubular body portion 2| and opposite end portions provided respectively with flanges 22 and 23. The

line l'! of Figform and construction flange 22 is rigidly secured in any suitable manner to casing ll, guide sleeve l1 being disposed thereby in subjacent relation to casing I l and in vertical alignment with an opening formed therein. The flange 23 extends radially from the lower end portion of guide sleeve l1 and is disposed on the right side thereof as viewed by one holding the tool, the unflanged part of the lower end portion of guide sleeve l1 being cut away as at 24 to form a set back from flange 23. The flange 23 is generally of sector shape as viewed in top plan (see Figure 2), its inner edge being coincident with the external surface of the tubular body portion 2| and its outer edge 26 being curved generally along an are having a center coincident with the vertical axis of the tubular portion 2!. The opposite side edges of the flange 23 are relatively convergent toward the central axis of portion 2 I, the side edge 21 being normal to the longitudinal axis of the casing H and generally tangent to the internal surface of the tubular body portion 2! while the opposite side edge 28 parallels a line extending radially from the central longitudinal axis of the tubular member 2i. In addition, the marginal edge 21 of the flange 23 is slightly tapered, as at 30.

The member :9 reciprocably mounted within the guide sleeve I! is made from round stock and is provided with a head portion 28 disposed above tubular sleeve 2 i, a body portion 3i reduced from the head portion 29 and siidably received by tubular sleeve 25, and a blade mounting portion 82 reduced from the body portion 31. Extending inwardly through a forward portion of flange 22 is a threaded guiding screw 33 having an end portion disposed to engage a V-groove 34 extend ing the full length of the head portion 25 and part way down the body portion 3 l.

The left side of the lower extremity of reciprocable member is is cut away to form a recess having a vertical base surface 36 and a horizontal end surface. The base surface 36 is provided with a channel 38 extending lengthwise thereof, and adjustably secured in channel 38 in a suitable manner is a blade 39 having a beveled cutting edge ii formed at the lower extremity thereof and disposed below the blade mounting portion 32. Extending transversely across the rear of the head portion 29 is an open out having a vertical base surface l2 and horizontal side surfaces 13 and M. The open cut receives a tubular sleeve having diametrically opposed portions disposed to abut respectively horizontal side surfaces t3 and i l for sliding movement lengthwise oi the open out, and the tubular sleeve over an eccentric end portion ll of main shaft ill.

The anvil it which forms an adjunct of the guide sleeve ll and with the latter depends from the casing ll, includes a deflector plate 48 intogrally formed with an attaching portion 49 and a blade holding portion 55 at opposite ends thereof. The attaching portion d9 of anvil i3 is cut away to form a depressed horizontal base surface 52 having a sharply defined shoulder 53. The attaching portion 3a is detachably rigidly secured in subjaccnt relation to flange 23 by means of threaded screws 55 which pass through openings in the latter and engage tapped aligned openings in the former, the heads or threaded screws 55 being disposed in suitable depressions which position the top of the screws flush with the upper surface of flange 23. When thus secured in place the horizontal base surface 52 and the shoulder 53 thereof abut respectively the lower face of flange 23 and the edge 21 of the 46 is fitted 4! latter, it being noted that the attaching portion 49 corresponds in outline with that of the flange 23 so that the corresponding edges of the parts 2.3 and 49 are substantially coincident when said parts are secured together.

The deflector plate ll! formed integrally with attaching portion 49 is of generally arcuate shape in top plan, the upper flat surface of the portion spiraling downward from the tapered surface 3% of flange 23 at one end thereof toward the other end thereof, the thickness of the de fleotor plate All being reduced from its outer peripheral edge Ed inward toward its inner edge 56. The latter edge follows a curvature of extremely small radius to provide an opening ill which laterally communicates with an openended notch 52 extending lengthwise of the shear head in the immediate region of the movable blade 39.

Extending downwardly from the depressed end of the spiral deflector plate 48 is the integrally formed blade-holding portion 5! in the form of a solid post of generally cylindrical shape. The right side of the post has a channel 59 out therein and extending lengthwise thereof, and adjustably secured in channel in a suitable manner is a blade 6i having a beveled cutting edge 52 formed at the upper extremity thereof and disposed above the blade holding portion 55 for coaction with cutting edge 4 i In operation, the casing ll of the tool is grasped by the operators hand, and when switch it is in its on position the motor l2 rotates main shaft it through gear train it. As the main shaft it rotates, the eccentric end portion fill thereof and the tubular sleeve h": carried thereby are moved bodily in a circular path. The horizontal component of such movement does not affect the action of member ii) because of the sliding movement of tubular sleeve in the rearwardly facing open cut in head portion 29, however, the vertical component of such movement eilects ver ical reciprocation of member iii in tubular body portion 2%. The end portion of guiding screw 33, which is disposed in V- groove 34, coacts therewith to keep reciprocating member ill from turning in tubular body portion 2! while at the same time permitting rela tive vertical sliding movement. It will be noted that when the reciprocable member is is in its lowermost position the body portion 3! thereof extends down to, but not beyond, the lower face of flange 23, the rounded surface of blade mounting portion 32 being set back from the opposed inner edge of attaching portion 43 of anvil it.

When the cutting blades 39 and are respectively mounted in position, the shearing edges ill and 62 thereof respectively are so angularly related as to permit free and easy feeding of sheet material to be out between and through the edges of the blades. Of course, in practice the tool is generally fed into and through the material along prescribed lines of out, during which operation the sheared edges of the material are respectively deflected above and below the deflector plate id so that one portion of the sheared material rests upon the upper surface of the deflector plate it and the other portion rides beneath the deflector plate d8 in close contact with its lower surface. It will be noted that on account of the smoothly merging upper surfaces of flange 23 and deflector plate ts, there is no obstruction to prevent the sheared material, resting upon the upper surface of deflector plate 48, from approaching the tubular sleeve 2i when cutting the material along a line curved to the right. In view of the foregoing, the line of such a cut may curve from a straight line to a curved line of a radius as small as that of the tubular sleeve 2|.

As a result of the impact from repeated shearing strokes, or from other cause, the anvil is sometimes injured or broken, and it will be understood that such damage to the tool may be repaired conveniently and cheaply by merely removing screws 55, placing a fresh anvil in position and then replacing the screws, and that applicant has provided a means for doing this without sacrifice in the utility at the tool.

It will be understood, of course, that the present invention is susceptible of various changes and modifications which may be made from time to time without departing from the general principles and real spirit of the invention, and accordingly, it is intended to claim the same broadly, as well as specifically, as indicated by the appended claim.

What is claimed as new and useful is:

In an operating head for a shearing tool having an electric motor carried by a casing adapted to be held in the operators hand, a sleeve adapted to be rigidly secured to the casing and in the normal use of the tool to depend therefrom, said sleeve being provided on one side at the lower extremity thereof with an external flange an elongated member provided withoutting means and mounted in said sleeve for axial movement, said elongated member being adapted for actuation by said motor, and an arcuately shaped anvil one end portion of which is disposed in underlying relation to said flange and detachably secured thereto, said flange and underlying anvil portion being substantially of the same thickness, said anvil being provided intermediate the opposite ends thereof with a laterally extending integral fillet. which abuts said flange, the fillet-abutting marginal flange portion being bevelled to provide a flange surface portion disposed in smooth continuation of the surface of said fillet and having substantially the same slope as said fillet, and said flange and anvil being provided with an upwardly presenting work supporting surface which includes the aforesaid surfaces of said fillet and abutting marginal flange portion and which spirals down- Wardly away from said flange around to the other side of said sleeve to the opposite end portion of said anvil, the latter end portion being provided with cutting means positioned for suitable coaction with said first mentioned cutting means.

References Cited in the file of this patent UNITED STATES PATENTS Niunber Name Date 2,454,728 White Nov. 23, 1948 30 2,482,582 Grafe Sept. 20, 1949 2,567,129 Schoffner Sept. 4, 1951 2,631,370 Gray Mar. 17, 1953 

